Created attachment 750937 [details]
Process definition which can be used to reproduce the problem.

** Description of problem:

A java.lang.NullPointerException will be thrown during parsing of the process if the definition (see attached file) contains 'xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"' elements and the process element is missing the 'id' attribute. 

** How reproducible:

File file = new File("/path/to/the/attached/process/definition");
Resource process = ResourceFactory.newFileResource(file);

KieServices ks = KieServices.Factory.get();
KieFileSystem kfs = ks.newKieFileSystem();
kfs.write(process);

KieBuilder kb = ks.newKieBuilder(kfs);
kb.buildAll();

** Actual results:

java.lang.NullPointerException on the kb.buildAll(); line.